Modular warming system for dialysis fluid

Abstract

An extremely lightweight and compact heating system greatly increasing patient mobility is provided. The use of a flat plate can be used to greatly decrease package size and weight while providing comparable heat transfer by exploiting the ability of the dialysis bags to conform to this surface and through the greater heating area possible with the flat plate design. A short rim around the plate provides centering and protecting against minor leakage without substantially increasing package height. Protection against leakage is buttressed by sealing the rim to the plate and the use of 12 V only within the heating unit. The result is a lightweight warming device with a short that can be easily transported by the patient greatly improving patient lifestyle and freedom.

We claim: 
     
       1. A warming module for infusible liquids comprising:
 an upwardly exposed planar metal warming plate sized to receive a flexible polymer bag holding the infusible liquid; 
 a polymer housing supporting the warming plate and providing an upwardly extending peripheral rim presenting a sealed continuous surface between the housing and the warming plate wherein the rim is continuous around a periphery of the warming plate and has a height less than 2 cm and an angle of less than 45 degrees with respect to the warming plate; 
 a heater element attached to the warming plate to conduct heat through the warming plate and bag into the contained infusible liquid when the bag is held on the warming plate; and 
 at least one light indicator comprising a light diffuser indicating a warming state of the flexible polymer bag holding the infusible liquid wherein the at least one light indicator is positioned to at least partially underlie and directly contact the flexible polymer bag to direct light into the flexible polymer bag; 
 wherein the flexible polymer bag extends above the rim permitting the warming state of the flexible polymer bag to be seen at a horizontal line of sight above the rim. 
 
     
     
       2. The warming module of  claim 1  wherein the heater element is attached to cover at least 90% of the warming plate area. 
     
     
       3. The warming module of  claim 1  wherein the heater element includes heater control circuitry and a remote wall adapter providing a voltage less than or equal to 12 V to the heater and heater control circuitry from the remote wall adapter through an adapter cord. 
     
     
       4. The warming module of  claim 1  wherein the warming module is less than five pounds. 
     
     
       5. The warming module of  claim 1  wherein the rim includes at least one proximity sensor detecting the presence of the bag on the plate to control the heater. 
     
     
       6. The warming module of  claim 5  wherein the at least one proximity sensor includes at least two proximity sensors that are displaced laterally from each other. 
     
     
       7. The warming module of  claim 6  wherein the at least two proximity sensors are displaced apart by at least 10 cm. 
     
     
       8. The warming module of  claim 5  wherein the at least one proximity sensor is an infrared sensor. 
     
     
       9. The warming module of  claim 1  wherein the at least one light indicator is supported by an inner surface of the rim. 
     
     
       10. The warming module of  claim 9  wherein the at least one light indicator is at least one light emitting diode bulb positioned beneath a light diffuser. 
     
     
       11. The warming module of  claim 10  wherein the at least one light emitting diode bulb and light diffuser are arranged around a perimeter of the housing. 
     
     
       12. The warming module of  claim 11  wherein the at least one light emitting diode bulb and light diffuser are arranged on the upwardly extending peripheral rim. 
     
     
       13. The warming module of  claim 9  wherein the at least one light indicator presents a warming state indicating that the bag is warming and is not at a predetermined temperature or is warmed to a predetermined temperature by means of a first color indicating that the bag is warming and a second color indicating that the bag is warmed to the predetermined temperature. 
     
     
       14. The warming module of  claim 9  wherein the at least one light indicator presents a warming state indicating that the bag is warming and is not at a predetermined temperature or is warmed to a predetermined temperature by means of changing an intensity of the light. 
     
     
       15. A warming system for infusible liquids comprising:
 at least two warming modules arranged in a stacked configuration along an axis extending along a height of each warming module, each warming module having
 an upwardly exposed planar metal warming plate sized to receive a flexible polymer bag holding the infusible liquid; 
 a polymer housing supporting the warming plate and providing an upwardly extending peripheral rim presenting a sealed continuous surface between the housing and the warming plate wherein the rim is continuous around a periphery of the warming plate and has a height less than 2 cm and an angle of less than 45 degrees with respect to the warming plate; 
 a heater element attached to the warming plate to conduct heat through the warming plate and bag into the contained infusible liquid when the bag is held on the warming plate; 
 at least one light indicator comprising a light diffuser indicating a warming state of the flexible polymer bag holding the infusible liquid wherein the at least one light indicator is positioned to at least partially underlie and directly contact the flexible polymer bag to direct light into the flexible polymer bag; 
 wherein the flexible polymer bag extends above the rim permitting the warming state of the flexible polymer bag to be seen at a horizontal line of sight above the rim. 
 
 
     
     
       16. The warming system of  claim 15  further including a mounting bracket having a first plate configured to be attached to the housing and a second plate extending perpendicular to the first plate and configured to be attached to a support element. 
     
     
       17. The warming system of  claim 15  wherein a spacing between the at least two warming modules is less than 15 cm. 
     
     
       18. The warming system of  claim 15  wherein a spacing between the at least two warming modules is less than two times a height of the bag when reposed on the warming plate. 
     
     
       19. The warming system of  claim 15  wherein the at least one light indicator is supported by an inner surface of the rim. 
     
     
       20. The warming system of  claim 15  wherein the at least one light indicator is at least one light emitting diode bulb positioned beneath a light diffuser.